AHTeamEPProtector03fakeASProtect10FEUERRADER

Hunt Hypothesis

This detection identifies potential adversary activity involving a specific YARA signature that flags suspicious endpoint protection behaviors associated with fake AS Protect components in Azure Sentinel environments. Proactively hunting for this indicator allows the SOC team to uncover early-stage evasion techniques or supply chain compromises before they escalate into critical incidents, despite the rule’s current low severity classification.

YARA Rule

rule AHTeamEPProtector03fakeASProtect10FEUERRADER
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 90 [46] 90 FF E0 60 E8 01 00 00 00 90 5D 81 ED 00 00 00 00 BB 00 00 00 00 03 DD 2B 9D }

condition:
		$a0 at pe.entry_point
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the AHTeamEPProtector03fakeASProtect10FEUERRADER detection rule, including suggested filters and exclusions:

• Scenario: Microsoft Defender Antivirus Scheduled Scan

  • Context: During off-hours (e.g., 2:00 AM), the Microsoft Defender Antivirus service (MsMpEng.exe) performs a full system scan. This process often spawns child processes that interact with network sockets or read large volumes of files, mimicking the behavior patterns of the “fake” protector logic defined in the YARA rule.
  • Suggested Filter/Exclusion: Add an exclusion for the process image path C:\Program Files\Windows Defender\MsMpEng.exe and its direct child processes when the parent command line contains keywords like /ScanType:Full or /Scheduled.

• Scenario: CrowdStrike Falcon Sensor Real-Time Protection Updates

  • Context: The CrowdStrike Falcon sensor (csfalcon.exe) frequently updates its real-time protection signatures. This update mechanism involves reading and writing to specific registry keys and monitoring file system events, which can trigger the AHTeamEPProtector signature due to similar heuristic behaviors in the “AS Protect” module.
  • Suggested Filter/Exclusion: Exclude processes where the image path matches C:\Program Files\CrowdStrike\FalconSensor\csfalcon.exe and the user context is SYSTEM. Additionally, filter out events occurring during the standard maintenance window (e.g., 03:00–05:00 local time).

• Scenario: SCCM/MECM Software Deployment Agent Activity

  • Context: When System Center Configuration Manager (SCCM) or Microsoft Endpoint Configuration Manager deploys a new application package, the ccmsetup.exe or `wuaagent